Polymerization of thiophene containing cyclobutadiene Co cyclopentadiene complexes

To understand the charge transport ability of the metal coordinated cyclobutadiene, a series of cyclobutadiene cobalt cyclopentadiene (CbCoCp) complexes containing electrochemically polymerizable thiophene units were synthesized. The complexes were electrochemically polymerized and the resulting polymers were characterized by cyclic voltammetry, in situ conductivity and UV–vis spectroelectrochemistry. Several different derivatives of the CbCoCp complexes and a model study suggested that if the oxidation of the organic fragment was above CoI/II redox couple of the CbCoCp complex, detrimental side reactions occured. Side reactions did not occurred if the oxidation of the organic fragment was below the metal oxidation.